Node migration

ABSTRACT

A method includes periodically sending an Advanced Meter Reading (AMR) beacon from a node at a first regular time interval, the AMR beacon containing a register identification and a reading detected by the node, and periodically listening, at the node, for a communication such that instances of listening occur at a second regular time interval smaller than the first time interval. In one aspect of the disclosure, the communication is a mobile command from a mobile transceiver. In another aspect of the disclosure, the communication is a Network System Status Request or a parent assignment command from a stationary transceiver.

TECHNICAL FIELD

This disclosure relates to socio-technical networks. More specifically,this disclosure relates to two-way communication with a node that wouldallow its use in a network exhibiting characteristics of two differentnetwork types.

BACKGROUND

A utility provider, such as a gas, electricity, or water provider, mayhave a large number of control, measuring, and sensing devices installedin the field in order to control transmission and distribution of theproduct, measure, and record product usage, and detect problems. Suchdevices may include water, gas, or electrical meters, remotelycontrolled valves, flow sensors, leak detection devices, and the like.Utility meters may include or be connected to wireless communicationdevices (nodes) that communicate through wireless communications withother communication devices to effect remote meter reading.

A traditional Advanced Meter Reading (AMR) system allows for onlyone-way communication between a node and another network device, such asa mobile (“drive-by”) collector. The node periodically emits a signal(herein also referred to as an “AMR beacon”) containing informationidentifying the node as well as a usage reading detected by the node.The node in a conventional AMR system does not receive any communicationfrom any device.

AMR networks evolved into Advanced Metering Infrastructure (AMI)networks, which are characterized by two-way communication between anode and another network device or devices. In a typical, fixed AMIconfiguration, an AMI system may comprise a central host capable ofconnecting via wired and/or wireless networking infrastructures to anumber of communication nodes, each node providing networkcommunications for one or more connected metering devices, controldevices, sensor devices, or the like. The AMI system may further includedata collection hubs, repeaters, gateways, and the like. Despite theadvantages presented by AMI networks over AMR networks (such asrobustness), many utility providers continue to use AMR networks becausethe costs of completely replacing an AMR network with an AMI network aresignificant. It would be desirable to have a system that is more easilymigrated from AMR to AMI.

SUMMARY

Disclosed are a system and method that periodically send an AMR beaconfrom a node at a first regular time interval, the AMR beacon containinga register identification and a reading detected by the node, andperiodically listen, at the node, for a communication such thatinstances of listening occur at a second regular time intervalpreferably smaller than the first time interval, thereby facilitatingefficient migration from AMR to AMI.

Various implementations described in the present disclosure may includeadditional systems, methods, features, and advantages, which may notnecessarily be expressly disclosed herein but will be apparent to one ofordinary skill in the art upon examination of the following detaileddescription and accompanying drawings. It is intended that all suchsystems, methods, features, and advantages be included within thepresent disclosure and protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and components of the following figures are illustrated toemphasize the general principles of the present disclosure.Corresponding features and components throughout the figures may bedesignated by matching reference characters for the sake of consistencyand clarity.

FIG. 1 is a block diagram showing one example of a modified AMR networktopology, according to embodiments described herein.

FIG. 2 is a block diagram showing one example of an AMI networktopology, according to embodiments described herein.

FIG. 3 is a block diagram of a node according to certain embodimentsdescribed herein.

FIG. 4 is a timing diagram showing example timing of both periodicsending of an AMR beacon from a node and periodic listening by the nodefor a communication.

FIG. 5 is a composite timing diagram enlarging a portion of the periodiclistening diagram illustrated in FIG. 4, and juxtaposing that portionwith a hailing pattern timing diagram of messages being sent alternatelybetween two hailing channels of the node.

FIG. 6 illustrates a flow diagram of an exemplary method showing stepsthat can be taken in a transition of a node from a modified AMR mode toan AMI mode.

FIGS. 7 and 8 illustrate a flow diagram of an exemplary method toimplement the “periodically listen for and process communication” step(block 604) of FIG. 6.

DETAILED DESCRIPTION

The present disclosure can be understood more readily by reference tothe following detailed description, examples, drawing, and claims, andtheir previous and following description. However, before the presentdevices, systems, and/or methods are disclosed and described, it is tobe understood that this disclosure is not limited to the specificdevices, systems, and/or methods disclosed unless otherwise specified,as such can, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularaspects only and is not intended to be limiting.

The following description is provided as an enabling teaching in itsbest, currently known embodiments. To this end, those skilled in therelevant art will recognize and appreciate that many changes can be madeto the various disclosed aspects described herein, while still obtainingthe beneficial results of the present disclosure. It will also beapparent that some of the desired benefits can be obtained by selectingsome of the features without utilizing or including other features.Accordingly, those who work in the art will recognize that manymodifications and adaptations are possible and can even be desirable incertain circumstances and are a part of the present disclosure. Thus,the following description is provided as illustrative of the principlesof the present disclosure and not in limitation thereof.

As used throughout, the singular forms “a,” “an” and “the” includeplural referents unless the context clearly dictates otherwise. Thus,for example, reference to “a panel” can include two or more such panelsunless the context indicates otherwise. As used herein, the terms“optional” or “optionally” mean that the subsequently described event orcircumstance may or may not occur, and that the description comprisesinstances where said event or circumstance occurs and instances where itdoes not.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect comprises from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another aspect. It will be furtherunderstood that the endpoints of each of the ranges are significant bothin relation to the other endpoint, and independently of the otherendpoint. For purposes of the current disclosure, a material property ordimension measuring about X on a particular measurement scale measureswithin a range between X plus an industry-standard upper tolerance forthe specified measurement and X minus an industry-standard lowertolerance for the specified measurement. Because tolerances can varybetween different materials, processes and between different models, thetolerance for a particular measurement of a particular component canfall within a range of tolerances.

FIG. 1 is a block diagram showing one example of a topology of a portionof a modified AMR network 10. “Modified” AMR as used herein indicates adifference from conventional AMR networks in that the network 10 permitslimited two-way communication with a node that not only sends AMRbeacons, but that also listens for communications that may come from astationary AMI device as well as from a mobile collector typically usedin AMR networks, as will be explained herein. Network 10 includes amobile (“drive-by”) collector 12 having a transceiver 14 moving in adirection such as shown by arrow 16, the movement provided by amotorized vehicle (not shown) on which the mobile collector 12 may bemounted or carried. The mobile collector 12 passes in sufficientproximity to nodes 18A,18B,18C (referred to herein generally as nodes18) to allow wireless communication between the nodes 18 and thecollector 12 through various communication links 20A,20B,20C (referredto herein generally as communication links 20). The communication links20 may include wireless communication links, such as radio frequency(“RF”) communication links. The transceiver 14 of the mobile collector12, together with a transceiver housed in each of the nodes (see FIG.4), primarily provide for one-way transmissions from the nodes 18 to thecollector 12. However, since it is occasionally desirable to communicatewith a node 18 from a collector, such as to obtain additional data, thismodified AMR system allows for two-way communication between the mobilecollector 12 and the nodes 18. Thus the mobile collector 12 may sendmobile commands across the communication links 20 to the nodes 18, asdisclosed further with regard to FIG. 5. The mobile collector 12 mayperiodically collect usage data, sensor data, and other data from thenodes 18 (including, for example, more detailed usage data from watermeters 22A,22B,22C) and forward data to a host 24, separated from theremainder of the elements of the network 10 by broken lines to indicatethat the host 24 is housed in a location remote from mobile collector 12when the mobile collector 12 is in transit collecting the data from thenodes 18. The host 24 may represent a combination of applicationservers, database servers, communication servers, web servers, and thelike that comprise the systems of the utility provider used to collectdata from, control, and manage the various communication nodes 18. Whenthe mobile collector 12 completes its collection of data from the nodes18, the mobile collector 12 is brought into sufficient proximity withthe host 24 to permit transfer of collected data to the host 24 via anysuitable data connection, such as with cables or wireless devices (notshown). Nodes 18A,18B,18C may be connected to water, gas, or electricalmeters, remotely controlled valves, flow sensors, leak detectiondevices, and the like (such as, respectively, water meters 22A,22B,22C).It will be appreciated that the term “node” as used herein may refer toeither a composite device in a network capable of performing a specificfunction or a communication module connected to such a device andconfigured to provide communications for the device with the mobilecollector 12. Any one of the nodes 18 sends an AMR beacon containing aregister identification (ID) and a reading detected by the node. Forexample, if one of the nodes 18 is part of, or connected to, a watermeter, then the AMR beacon includes a register ID and datarepresentative of a reading of the water meter.

FIG. 2 is a block diagram showing one example of a network topology ofan illustrative fixed AMI system 100, such as that implemented by autility provider. The AMI system 100 may include utility providersystems, such as host 102. The host 102 may represent a combination ofapplication servers, database servers, communication servers, webservers, and the like that comprise the systems of the utility providerused to collect data from, control, and manage the various nodes 18D-18G(referred to herein generally as nodes 18) in the AMI system 100. Forexample, as shown in FIG. 2, nodes 18F,18D,18G may be respectivelyconnected to water meters 22F,22D,22G and provide AMI networkcommunication for the device.

According to various embodiments, the host 102 may communicate with thenodes 18 through one or more stationary collection hubs 108. Thestationary, or fixed, collection hubs 108 may comprise specializednetwork nodes installed in the field that act as a “parent node” for aset of assigned child nodes 18D-18G that communicate with the hubthrough various communication links 110A-110E (referred to hereingenerally as communication links 110). The communication links 110 mayinclude wireless communication links, such as RF communication links.Owing to a stationary transceiver 109 housed in each hub 108, thecommunication across the communication links 110 is two-way. Thecollection hubs 108 may periodically collect usage data, sensor data,and other data from the child nodes 18 and forward data to the host 102over a network 112. The collection hubs 108 may also forward messagesreceived from the host 102 over the network 112 to the target childnode(s) 18. The network 112 may comprise various networking technologiesthat connect the collection hubs 108 in the field to the host 102,including cellular data networks, Wi-Fi or WiMAX networks, satellitecommunication networks, metropolitan-area networks (“MANs”), wide-areanetworks (“WANs”), the Internet, and the like.

A collection hub 108 may communicate with its child nodes 18D-18G eitherdirectly or through one or more intermediary devices. For example, theAMI system 100 may include repeaters 114 that facilitate communicationbetween the collection hub 108 and remote nodes, such as node 18G.According to further embodiments, some nodes may be configured to act asrepeaters, referred to herein as “buddy nodes,” such as node 18E shownin FIG. 2. It will be appreciated that some nodes in the AMI system 100,such as node 18D, may be located such that it receives messages from thecollection hub 108 both directly and by way of one or more repeaters 114or buddy nodes.

According to embodiments, the collection hubs 108 may include or beconnected to an accurate time source 118. For example, a collection hub108 may be GPS-enabled and able to receive a highly accurate time valuefrom a GPS receiver. Other accurate time sources 118 may include acellular network connection, an integrated accurate real-time clockcomponent, and the like. Because collection hubs 108 may be connected tofixed power sources, these devices may be able to maintain accuratecurrent time without the need for reduced power consumption required byother, remote nodes, such as node 18G. It will be appreciated that theconfiguration of the network comprising the AMI system shown in FIG. 1and described above is merely one configuration, and additional devicesand/or alternative configurations may be conceived by one skilled in theart. As such, the network topology shown in FIG. 1 and the networkconfigurations described should not be seen as limiting but, instead, asmerely exemplary.

The communication links shown in FIGS. 1 and 2 represent a network ornetworks that may comprise hardware components and computersinterconnected by communications channels that enable sharing ofresources and information. The network may comprise one or more of awired, wireless, fiber optic, or remote connection via atelecommunication link, an infrared link, a radio frequency link, acellular link, a Bluetooth® link, or any other suitable connectors orsystems that provide electronic communication. The network may compriseintermediate proxies, routers, switches, load balancers, and the like.The paths followed by the network between the devices as depicted inFIGS. 1 and 2 represent the logical communication links between a nodeand a mobile collector 12 (FIG. 1), and a node and a hub (FIG. 2), notnecessarily the physical paths or links between and among the devices.

FIG. 3 shows a block diagram of components of an illustrative node 18configured for RF communication in AMR and AMI networks. In other words,the node 18 is able to operate in an AMI mode or in a modified AMR mode.The node 18 may allow data to and from devices in the AMI system 100,such as water, gas, or electrical meters, remotely controlled valves,flow sensors, leak detection devices, collection hubs 108, repeaters114, and the like, to be communicated over the wireless AMI network. Forexample, the node 18 may be implemented in or connected to water meters(as in FIGS. 1 and 2) or to a leak detection device in order to transmitaudio recording data to the host 102 for leak detection. According tovarious embodiments, the node 18 may be configured for communication onvarious radio network topologies, including star, hybrid-star,peer-to-peer, mesh, and the like.

The node 18 may include a battery 205 that powers a transceiverintegrated circuit (“IC”) 210, a processor 220, an RF power amplifier230, an RF low-noise amplifier 240, a memory 250, and other components.Crystal oscillators 215 and 225 are connected to the transceiver IC 210and the processor 220, respectively. The node 18 further includes atransmit/receive switch 260 and antenna 270. The processor 220 may be amicroprocessor, a microcontroller, a field-programmable gate array(“FPGA”), or the like. The processor 220 and the transceiver IC 210 mayinclude both a two-way data and a two-way control line. In someembodiments, the processor 220 includes a control line to each of the RFlow-noise amplifier 240 and the transmit/receive switch 260. Theprocessor 220 may also be connected to the memory 250 by a two-way dataline.

The memory 250 may comprise a processor-readable storage medium forstoring processor-executable instructions, data structures and otherinformation. The memory 250 may include a non-volatile memory, such asread-only memory (“ROM”) and/or FLASH memory, and a random-access memory(“RAM”), such as dynamic random access memory (“DRAM”) or synchronousdynamic random access memory (“SDRAM”). The memory 250 may storefirmware that comprises commands and data necessary for the nodes 18,collection hubs 108, and repeaters 114 to communicate with other devicesin the AMI system 100 as well as perform other operations of the nodes.According to some embodiments, the memory 250 may store a migrationmodule 252 comprising processor-executable instructions that, whenexecuted by the processor 220, perform at least portions of the routine600 (including the method at block 604) for controlling AMR beacons andmigrating the node 18 from a modified AMR mode to an AMI mode.

In addition to the memory 250, the node 18 may have access to otherprocessor-readable media storing program modules, data structures, andother data described herein for accomplishing the described functions.It will be appreciated by those skilled in the art thatprocessor-readable media can be any available media that may be accessedby the processor 220 or other computing system, includingprocessor-readable storage media and communications media.Communications media includes transitory signals. Processor-readablestorage media includes volatile and non-volatile, removable andnon-removable storage media implemented in any method or technology forthe non-transitory storage of information. For example,processor-readable storage media includes, but is not limited to, RAM,ROM, erasable programmable ROM (“EPROM”), electrically-erasableprogrammable ROM (“EEPROM”), FLASH memory or other solid-state memorytechnology, compact disc ROM (“CD-ROM”), digital versatile disk (“DVD”),high definition DVD (“HD-DVD”), BLU-RAY or other optical storage,magnetic cassettes, magnetic tape, magnetic disk storage or othermagnetic storage devices and the like.

According to embodiments, the processor 220 may be further connected toother components of the node 18 through a device interface 280. In someembodiments, the device interface 280 may connect to a meteringcomponent, such as a water, gas, or electricity meter, that allows themeter to provide usage data to the host 102 through the AMI system 100.In further embodiments, the device interface 280 may connect to sensorsor detection components. In still further embodiments, the deviceinterface 280 may connect to a control component, such as anelectronically actuated water valve, that allows the host 102 and/orother devices in the AMI system 100 to control aspects of the utilityprovider's infrastructure. These examples are not meant to be limiting,and those of skill in the art will recognize that alternative devicecomponents that may be interfaced with the node 18 through the deviceinterface 280. For example, the device interface 280 may connect to acontrol component (valve actuator) and a data reading port (water meterreadings) at the same time.

It will be appreciated that the structure and/or functionality of thenode 18 may be different than that illustrated in FIG. 3 and describedherein. For example, the transceiver IC 210, processor 220, RF poweramplifier 230, RF low-noise amplifier 240, memory 250, crystaloscillators 215, 225, device interface 280 and other components andcircuitry of the node 18 may be integrated within a common integratedcircuit package or distributed among multiple integrated circuitpackages. Similarly, the illustrated connection pathways are providedfor purposes of illustration and not of limitation, and some componentsand/or interconnections may be omitted for purposes of clarity. It willbe further appreciated that the node 18 may not include all of thecomponents shown in FIG. 3, may include other components that are notexplicitly shown in FIG. 3 or may utilize an architecture completelydifferent than that shown in FIG. 3.

Referring to FIG. 4, showing a timeline 30, each node 18 sends AMRbeacons such as at 32A-32D (arrows also designated by the letter “S,”for “send”; AMR beacons referred to collectively as “AMR beacons 32”)periodically, meaning that the AMR beacons 32 repeatedly occur at aregular time interval 34, an example of such an interval 34 being in therange of 1 to 30 seconds, such as the six seconds shown in FIG. 4. Inone implementation, the nodes 18 repeatedly send the AMR beacons 32 at apower of about 15 dBm, and at a frequency of about 915 MHz. Each node 18also periodically listens for a communication, such as a hailing messagefrom the mobile collector 12 (see FIG. 1) or stationary collector or hub108 (see FIG. 2), meaning that instances of listening, such as at36A-36G (collectively referred to herein as listening instances 36,shown by arrows designated with the letter “L” for “listening”),preferably occur at a regular time interval 38 smaller than the regulartime interval 34. An example of regular time interval 38 is in the rangeof 0.5 to 30 seconds, such as the three seconds as shown in FIG. 4. Theinitial instance of listening 36A occurs after the initial AMR beacon32A, the initial instance 36A being separated from the initial AMRbeacon 32A by an offset 40, which may have a magnitude in the range of0.2 to 10 seconds, such as the one second shown in FIG. 4. In the shownembodiment, similar timing and similar messaging protocols are utilizedfor signals from stationary and mobile collectors, thereby reducingcomplexity and preserving battery life. However, other embodimentsinclude different timing and communication protocols for mobile andstationary communications with the nodes 18.

In some embodiments, nodes 18 in the networks illustrated in FIGS. 1 and2 may employ frequency-hopping spread spectrum (“FHSS”) technology totransmit and receive data between them. For example, the nodes 18 may beconfigured to comply with F.C.C. rules and regulations (part 15) (47C.F.R. § 15). FHSS is a method of transmitting and receiving radiosignals by rapidly switching among many frequency channels using apseudorandom channel sequence known to both the transmitting andreceiving devices. In some embodiments, hailing channels and datachannels are selected from the 902-928 MHz industrial, scientific, andmedical (“ISM”) bandwidth. Battery-powered (DC) nodes of the typeillustrated in FIG. 3 may not be able to afford to expend the energy tocontinuously monitor as many as 50 FHSS channels, so between 1 and 20,such as 16, non-FHSS channels may be reserved for hailing ofbattery-powered nodes 18. In some examples, the 16 non-FHSS channels maybe 500 kHz wide channels. Each battery-powered node 18 may be assignedtwo (a set) of these non-FHSS channels to monitor for incoming hailingmessages. In other implementations there may only be one hailing channeland in still other implementations, there may be more than 2 hailingchannels, in which case the alternating would simply rotate through allhailing channels successively. Thus, nodes 18 performing listeninginstances 36 through, in some implementations, a channel activitydetection process that includes listening for a hailing message during ahailing listening period, or instance, on the set of the plurality ofnon-FHSS channels. In examples, nodes 18 may utilize an RF chipset (forexample, Semtech's LoRa RF chipset for transceiver IC 210 and otherelements, as controlled by programming in memory 250), which may includean integrated or connected channel activity detector (CAD). The CAD canquickly assess whether any RF energy exists in a channel that matches apreamble transmission profile. A preamble represents a sequence ofsymbols that may be repeated at the start of a data message, including ahailing message. A preamble may precede any valid messages, includinghailing messages. The preamble can be detected and decoded, enabling,for example, a receiving node 18 to distinguish between a valid,intended message and other data (e.g., noise, data intended for otherdevices, data from another network, etc.). In an example, the preamblemay represent a known sequence of symbols that may be, for example, six(6) symbols, although other numbers of symbols are also possible and maybe utilized in various implementations.

If the CAD detects the possibility of an incoming message as a result ofdetecting energy in a channel that matches the preamble transmissionprofile, the chipset enters a mode to receive the data preceded by thepreamble. Such detection may be referred to as “performing a CAD” or“completing a CAD.” In performing a CAD, the channel activity detectorlooks at one symbol at a time and verifies if the RF signature matches apreamble. If such a match occurs after detection of one symbol, thechannel activity detector looks at between 3 and 10 more preamblesymbols (such as five (5) more preamble symbols) for verification thatthe matter being detected is, in fact, a preamble. It may take a totalof about 3 ms to complete a CAD on both of the monitored channels, oneafter the other, as a CAD can be completed upon detection of, forexample, six (6) preamble symbols. Devices hailing on the non-FHSSchannels use a message with approximately 160 ms of preamble, in oneimplementation. The hail message is repeated several times until areceiving node 18 detects and acknowledges the hail from a hailingdevice, as explained further below. In other words, the repeating of thehail message only occurs so long as a device hailing the receiving node18 did not receive an acknowledgement from the receiving node.

In examples such as that previously described with regard to FIG. 4, abattery-powered node 18 samples for incoming messages at a relativelyslow rate. Referring to FIG. 5, in order to successfully hail abattery-powered node 18, a repeating pattern of hail messages is sent.An example of a source of hail messages is a hailing device (such as hub108 or repeater 114 in FIG. 2). FIG. 5 juxtaposes an enlarged portion ofthe periodic listening diagram shown in FIG. 4 with a hailing patterntiming diagram 42 of messages being sent alternately between two hailingchannels (shown as Channel A and Channel B) of a node 18. With theenlargement resulting in FIG. 5, the instances of listening 36A and 36Bare isolated from the remaining listening instances shown in FIG. 4, andinitial AMR beacon 32A is isolated from the remaining AMR beacons32B-32D shown in FIG. 4. Additionally, the instances of listening 36Aand 36B have been moved above the timeline 30 alongside the initial AMRbeacon 32A, for clarity of illustration in relation to the hailingpattern timing diagram 42, described below.

FIG. 5 shows a hailing pattern timing diagram 42 representing a pattern,or sequence, of hail messages 44A-44F (collectively referred to hereinas hail messages 44) from a hailing device, such as the hub 108 and,more particularly, such as from stationary transceiver 109 (FIG. 2)within hub 108. Each hail message 44 may include, in one implementation,approximately 160 ms of preamble and 20 ms of data, for a hail durationof approximately 180 ms, or 0.18 s. Thus, the three-second period 38spanning each listening instance 36 is between sixteen and seventeentimes larger than the hail duration, since 3 divided by 0.18 is about16.67. Each hail message 44 is followed by a period “RX” ofapproximately 22 ms where the hailing device tries to receive theresponse (acknowledgement, or “ACK signal”) from a receiving node (alsocalled a “target node” and exemplified at node 18F, 18D, and 18G in FIG.2) on an FHSS channel referenced in the hail message 44. FIG. 5 does notshow the entirety of the preamble period of hail message 44E since breakline segments 46A,46B interrupt it (though they could have been locatedanywhere along the length of the diagram 42) to indicate that more hailmessages are present in the hail pattern during the 3-second regulartime interval 38 than are actually shown in FIG. 5. In examples, such asthe hailing pattern timing diagram 42 illustrated in FIG. 5, the hailmessages are sent alternating between two hailing channels of thereceiving node 18 (target node). As shown in FIG. 5, hail messages 44A,44C, and 44E are sent on Channel “A,” and hail messages 44B, 44D, and44F are sent on Channel “B.”

FIG. 5 indicates which portions of each hail message 44 are valid andinvalid, for purposes of being able to detect a hail message. Areceiving node 18 can only detect a hail message during the preambleperiod except for the last few milliseconds thereof, as shown in FIG. 5.Detection of a hail message cannot occur when the hailing device istransmitting data or when it is waiting for the acknowledgement signalfrom the receiving node 18; thus, for each hail message 44, the “InvalidCAD” periods in FIG. 5 are each shown extending across an “RX” period,across a “Data” period, and extending slightly into the end of eachpreamble period, which shown by dimension line segments such as at 45.Line segment 45 is intended to show that, in one implementation, a CADcannot be completed for the last five (5) preamble symbols appearingwithin the 160 ms preamble period of a hail message 44, since usuallydetection of at least six (6) preamble symbols is required for CADcompletion. A start frame 47 separates the preamble portion of a hailmessage from the data portion. The start frame 47 indicates that thenext matter to be transmitted is going to be data and not preamblesymbols.

In one implementation, the detection of hail messages in the mannerdiscussed with regard to FIGS. 4 and 5 is the same regardless of whetherthe hail message was sent by a mobile collector 12 in a modified AMRnetwork or by a fixed AMI network device such as hub 108. The timing ofthe hail messages 44 and gap between instances of listening is such thatif an instance of listening falls within an invalid period for one hailmessage, a next instance of listening will fall within a valid timeperiod for a later hail message, enabling a successful hail. Forexample, FIG. 5 shows that initial instance of listening 36A may fallwithin an invalid period, such as an RX period following hail message44A, when the hailing device awaits an acknowledgement from thereceiving node 18. Three seconds later, however, the next instance oflistening 36B falls within a valid CAD window of hail message 44F.

Embodiments of the methods and systems are described below withreference to block diagrams and flowchart illustrations of methods,systems, and apparatuses. It will be understood that each block of theblock diagrams and flowchart illustrations, and combinations of blocksin the block diagrams and flowchart illustrations, respectively, can beimplemented by program instructions. These program instructions may beprogrammed into programmable processing elements to produce logic thatexecutes on the processing elements to create means for implementing thefunctions specified in the flowchart block or blocks, which describe andreference specific algorithms and inherent structure for accomplishingthe functions as described and further explained herein.

These program instructions may also be stored in a processor-readablememory that can direct a processing apparatus to function in aparticular manner, such that the instructions stored in theprocessor-readable memory produce an article of manufacture includingprocessor-readable instructions for implementing the function specifiedin the flowchart block or blocks. The program instructions may also beloaded onto a processing apparatus to cause a series of operationalsteps to be performed on the programmable apparatus to produce aprocessor-implemented process such that the instructions that execute onthe programmable apparatus provide steps for implementing the functionsspecified in the flowchart block or blocks.

Accordingly, blocks of the block diagrams and flowchart illustrationssupport combinations of means for performing the specified functions,combinations of steps for performing the specified functions and programinstruction means for performing the specified functions. It will alsobe understood that each block of the block diagrams and flowchartillustrations, and combinations of blocks in the block diagrams andflowchart illustrations, can be implemented by special purposehardware-based systems that perform the specified functions or steps, orcombinations of special purpose hardware and instructions.

It is contemplated that the processor of the present application canoperate in a networked environment using logical connections to one ormore remote devices. By way of example, a remote device can be apersonal computer, portable computer, a server, a router, a networkcomputer, a peer device or other common network node, and so on. Logicalconnections between the processor and a remote computing device can bemade via a local area network and a general wide area network. Suchnetwork connections can be through a network adapter. It is furthercontemplated that such a network adapter can be implemented in bothwired and wireless environments, which are conventional and commonplacein offices, enterprise-wide computer networks, intranets, and theInternet.

It is recognized that programs and components reside at various times indifferent storage components of a device. Any of the disclosed methodscan be performed by processor readable instructions embodied onprocessor-readable media. Such media can be any available media that canbe accessed by a processor. By way of example and not meant to belimiting, processor readable media can comprise volatile andnon-volatile, removable and non-removable media implemented in anymethods or technology for storage of information.

FIG. 6 illustrates a flow diagram of a method 600 showing steps that canbe taken in a transition of a single node 18 from a modified AMR mode toan AMI mode. Method 600 begins at block 602, where the node 18periodically sends its AMR beacon, in the manner discussed with regardto FIGS. 4 and 5. At block 604, the node 18 periodically listens for acommunication, in the manner discussed with regard to FIGS. 4 and 5.Also at block 604, the node 18 processes the communication in the mannerdetailed below with regard to FIGS. 7 and 8, and the double border ofblock 604 signifies that it includes subsidiary processing steps, asdisclosed in those figures. The listening step of block 604 is shown forpurposes of illustration to sequentially follow the beacon sending stepof block 602 since, referring to FIG. 4, the initial AMR beacon 32Aprecedes the initial instance of listening 36A (by the offset 40). It isto be understood, however, that despite the sequential representation ofblocks 602 and 604 in FIG. 6, and consistent with the above discussionof FIG. 4, multiple instances of listening may be represented by step604 and precede the next AMR beacons. For instance, in FIG. 4, the firsttwo instances of listening 36A,36B precede the next AMR beacon 32B. Inaddition, because of the sequential processing represented in FIG. 4,extended time may be spent in block 604 that will delay AMR beacon suchthat the periodicity of the beacons is delayed or ceased entirely, as isrepresented by step 608. However, before proceeding in detail to theremaining blocks of method 600, discussion of the communicationprocessing steps of FIGS. 7 and 8 is useful.

FIG. 7 illustrates the first sequence of blocks describing thecommunication processing method represented by block 604 of FIG. 6. Atblock 702, a receiving node 18 listens for a communication (here, a hailmessage) on a pair of alternating hailing channels in the mannerdiscussed with regard to FIGS. 4 and 5. At decision block 704, it isdetermined whether, in this particular implementation, five valid(consecutive) preamble symbols have been detected. If no such detectionoccurs, then the method of block 604 proceeds directly to block 606 ofFIG. 6. Since no hailing message was received, no data could bereceived, such as a parent assignment command, resulting in the processcontinuing in block 602 and the modified AMR mode continuing. If,however, the receiving node 18 successfully detects five consecutivepreamble symbols, i.e., valid channel activity is detected (which canhappen in other ways in other embodiments), which suggests a hailmessage may be available in a subsequent data window, the methodadvances to decision block 706. In the present implementation, thesending of the AMR beacons has effectively been suspended becausecommunication processing continues in the method of block 604. No AMRbeacons are sent until and unless method 600 (FIG. 6) reaches the “NO”line running from block 606 to block 602. In other implementations,suspension of AMR beacons may happen in other ways, i.e., a flag or somesort of inter process communication that actively suspends an otherwiseindependent beaconing thread. In decision block 706, it is determinedwhether data received after the preamble symbols includes a hail messagecontaining the node ID of the receiving node 18. Other implementationsinclude other methods of determining if a hailing message is valid forthe node 18, including other implementations of directed hailingmessages as well as broadcast messages that are not directed to anyparticular node 18. If no hailing message to be acted upon by the node18 is detected, then the method of block 604 again goes directly toblock 606 of FIG. 6. If, however, the receiving node 18 detects its nodeID in the hail message, then the method of block 604 advances to block708, where the receiving node 18 hops from the hailing channel, on whichit received the hail message, to a data channel identified in the hailmessage. The method of block 604 then reaches block 710, where thereceiving node 18 sends an ACK signal to the hailing device over thedata channel to which the node 18 hopped at block 708. At decision block712 it is determined whether stable two-way (FHSS) communication has nowbegun with the hailing device (i.e., a valid message, such as a command,has been received from the hailing device) or if an additional hail fromthe hailing device is needed, such as if the hailing device failed toreceive the ACK signal shown in step 710. If it is determined that anadditional hail is needed, the method of block 604 loops back to block702, where the receiving node 18 once again listens for a hail messageon a hailing channel, and the method repeats through the blockspreviously described above. That repeated attempt will again involvechecking both hailing channels. If, however, it is determined at block712 that no additional hail is needed, then the method of block 604advances to block 714, where the receiving node 18 begins analyzing anyadditional data received from the hailing device, since by this point asuccessful hail has been acknowledged. An additional communication fromthe hailing device is needed for the node 18 to take an action. Once thereceiving node 18 finishes analyzing the data, or message, received onthe FHSS channel, the method of block 604 advances to flow chart marker716 (shown as an encircled “A”), provided for purposes of illustrationto connect the flow chart portion of FIG. 7 with the flow chart portionof FIG. 8, described below.

FIG. 8 continues the flow chart for the method of block 604 at the flowchart marker 716. At this point, the receiving node 18 has finishedanalyzing the data from the hailing device, as described with regard toblock 714 of FIG. 7. The method continues from the flow chart marker 716to decision block 718, where it is determined whether the receiving node18 received a mobile command from a mobile collector 12, i.e., in thiscase a mobile collector 12 was the hailing device. If so, the methodadvances to block 720, where the node 18 executes the mobile command,which may include instructions for the node 18 to, for instance, performan action, such as to shut off a valve with which the node 18 may beassociated. The instructions in the mobile command may instead directthe node 18 to send the mobile collector 12 a specified communication,such as a single reading or a series of readings over a predeterminedtime period. Any reply communication from the node 18 to the mobilecollector 12 is, in one aspect of the present disclosure, sent at apower of about 15 dBm, and at a frequency of about 915 MHz. Theinstructions could also instruct the node 18 to both perform a task andsend a communication. If desired for a hailed connection, the method ofblock 604 may also include steps representing the sending of anacknowledgement signal by the receiving node 18 to the originator of themobile command (in this case, mobile collector 12) following receipt ofthe mobile command, and representing the re-sending of the mobilecommand upon failure of the originator to receive an acknowledgementfrom the receiving node 18. Following execution of the mobile command atblock 720, the method of block 604 proceeds to decision block 722.

If no mobile communication was received, however, the method of block604 proceeds directly from decision block 718 to decision block 722. Atdecision block 722, a determination is made as to whether the receivingnode 18 has received a Network System Status Request (NSSR), orequivalent, from a hailing device, such as from the stationarytransceiver 109 in hub 108, also referred to as a collector. If not,then the method again skips to block 606 of FIG. 6, to be describedherein. If, however, the receiving node 18 has received an NSSR from thestationary transceiver, then the method of block 604 advances to block724, where the node 18 sends an ID communication to the stationarytransceiver in response to the NSSR, the ID communication containingboth a node ID for node 18 (used for AMI communications) and theregister ID for the meter register to which it is connected (used forAMR communications). This ID communication from the node 18 is, in oneaspect of the present disclosure, sent at a power of about 20 dBm, andat a frequency of about 915 MHz. If desired for a hailed connection, themethod of block 604 may also include steps representing the sending ofan acknowledgement signal by the receiving node 18 to the originator ofthe NSSR (i.e., the stationary transceiver 109) following receipt of theNSSR, and representing the re-sending of the NSSR upon failure of theoriginator to receive an acknowledgement from the receiving node 18.Block 724 marks the end of the flow chart of FIGS. 7 and 8, and thus theend of the method of block 604, so the method proceeds from block 724 toblock 606 of FIG. 6, described below.

Referring again to FIG. 6, at decision block 606, it is ascertainedwhether the receiving node 18 has also received a parent assignmentcommand from the stationary transceiver 109 in the hub 108. If receivedat block 606, the parent assignment command is interpreted as aninstruction that the node 18 continue in AMI mode to receive all furthercommunications from a stationary transceiver (such as hub 108)identified in the parent assignment command, and to stop sending AMRbeacons. Thus, the parent assignment command causes the node 18 totransition to an AMI mode, as shown at block 608. Once in AMI mode, thenode 18 may receive and execute further commands from the stationarytransceiver 109, such as a command to perform periodic uploads of datacollected by the node 18, with the periodic uploads to occur at timeintervals specified in the command, for example. If, however, the node18 does not receive a parent assignment command, method 600 loops backto block 602, where the node 18 resumes sending its AMR beacons. Otherimplementations include other methods of determining whether a hailingdevice is effectively instructing the node 18 to switch to an AMI mode,e.g., the NSSR message itself could be interpreted as such a commandwithout waiting for a parent assignment command. Additional processesalso may be included, and it should be understood that the processesdepicted in FIGS. 6-8 represent illustrations, and that other processesmay be added or existing processes may be removed, modified, orrearranged without departing from the scope and spirit of the presentdisclosure.

Although several embodiments have been disclosed in the foregoingspecification, it is understood by those skilled in the art that manymodifications and other embodiments will come to mind to which thisdisclosure pertains, having the benefit of the teaching presented in theforegoing description and associated drawings. It is thus understoodthat the disclosure is not limited to the specific embodiments disclosedhereinabove, and that many modifications and other embodiments areintended to be included within the scope of the appended claims.Moreover, although specific terms are employed herein, as well as in theclaims which follow, they are used only in a generic and descriptivesense, and not for the purposes of limiting the described disclosure,nor the claims which follow.

That which is claimed is:
 1. A method, comprising: periodically sendingan Advanced Meter Reading (AMR) beacon from a node at a first regulartime interval, the AMR beacon containing a register identification (ID)and a reading detected by the node; periodically listening, at the node,for a communication such that instances of listening occur at a secondregular time interval smaller than the first regular time interval; andreceiving the communication at the node; wherein the communication is arepeating pattern of hail messages, and wherein each hail message has ahail duration smaller than the second regular time interval.
 2. Themethod of claim 1, wherein the hail messages alternate between at leasttwo hailing channels of the node.
 3. The method of claim 1, whereininstances of listening by the node have a timing with respect to therepeating pattern of hail messages such that if an instance of listeningfalls within an invalid period for one hail message, a next instance oflistening will fall within a valid period for a later hail message,enabling a successful hail.
 4. The method of claim 1, wherein the secondregular time interval is between 16 and 17 times larger than the hailduration.
 5. The method of claim 4, wherein the hail duration is about180 milliseconds (ms).
 6. The method of claim 1, wherein an initialinstance of listening occurs after an initial AMR beacon and isseparated from the initial AMR beacon by an offset ranging from andincluding about 0.2 seconds to and including about 10 seconds.
 7. Themethod of claim 1, wherein the first regular time interval ranges fromand including about 1 second to and including about 30 seconds, thesecond regular time interval ranges from and including about 0.5 secondsto and including about 30 seconds, and the node repeatedly sends the AMRbeacon at a power of about 15 dBm, and at a frequency of about 915 Mhz.8. The method of claim 1, further comprising receiving a mobile commandat the node.
 9. The method of claim 8, further comprising executing themobile command by performing an action selected from a group consistingof performing a task, sending a reply communication, and both performinga task and sending a reply communication.
 10. The method of claim 9,wherein any reply communication from the node is sent at a power ofabout 15 dBm, and at a frequency of about 915 Mhz.
 11. The method ofclaim 1, further comprising: receiving at the node a Network SystemStatus Request (NSSR) from a stationary transceiver; and sending anidentification (ID) communication from the node in response to the NSSR,the ID communication containing both a node ID and the register ID. 12.The method of claim 11, further comprising receiving, at the node, aparent assignment command, the parent assignment command causing thenode to transition to an Advanced Metering Infrastructure mode.
 13. Themethod of claim 1, further comprising: receiving data from a stationarytransceiver; processing the data to determine whether the periodicsending of the AMR beacons should be halted; and halting the sending ofthe AMR beacons responsive to a determination that the data comprises aninstruction to stop sending AMR beacons.
 14. A node, comprising: aprocessor; and logic processed by the processor to periodically send anAdvanced Meter Reading (AMR) beacon from the node at a first regulartime interval, the AMR beacon containing information identifying thenode and containing a reading detected by the node, periodically listen,at the node, for a communication such that instances of listening occurat a second regular time interval smaller than the first regular timeinterval, and receive the communication at the node, wherein thecommunication is a repeating pattern of hail messages, and wherein eachhail message has a hail duration smaller than the second regular timeinterval.
 15. The node of claim 14, wherein the logic is furtherprocessed by the processor to detect hail messages alternating betweenat least two hailing channels of the node.
 16. The node of claim 14,wherein the logic is further processed by the processor to timeinstances of listening by the node with respect to the repeating patternof hail messages such that if an instance of listening falls within aninvalid period for one hail message, a next instance of listening willfall within a valid period for a later hail message, enabling asuccessful hail.
 17. The node of claim 14, wherein the logic is furtherprocessed by the processor to: receive at the node a Network SystemStatus Request (NSSR) from a stationary transceiver; and send anidentification (ID) communication from the node in response to the NSSR,the ID communication containing both a node ID and a register ID. 18.The node of claim 17, wherein the node is further processed by theprocessor to: receive a parent assignment command; and cause the node totransition to an Advanced Metering Infrastructure mode in response toreceipt of the parent assignment command.
 19. The node of claim 14,wherein the logic is further processed by the processor to: receive datafrom a stationary transceiver; process the data to determine whether theperiodic sending of the AMR beacons should be halted; and halt thesending of the AMR beacons responsive to a determination that the datacomprises an instruction to stop sending AMR beacons.